In Iceland, mineral based turf has been used as a building material for centuries. In this study the impact of Icelandic turf structures on occupant health is examined. Historical epidemiological and demographic figures have been studied, as well as building materials and geometry, biological contaminants, and the indoor environment of the Icelandic turf farm of Glaumbær. The occupants’ health was not influenced by building properties that are characteristic to turf structures. Disease prevalence seems to have originated from the poor living conditions occupants were exposed to. Despite primitive living conditions, some of the Icelanders reached very high ages.